In U.S. Pat. No. 7,159,687 issued 1 Sep. 2007 based on an application filed Apr. 28, 2005, and Canadian application Serial No: 2,505,458, filed Apr. 27, 2005 entitled TRACTOR WITH REVERSIBLE OPERATOR POSITION FOR OPERATION AND TRANSPORT is disclosed a swather tractor for transporting a header of the type with which the present invention is concerned. The tractor has a frame, a pair of hydraulically driven ground drive wheels at a first end of the frame, a pair of castor wheels at a second end of the frame and a pair of header lift arms at the first end of the frame and is arranged such that it can be driven with the first end forward and for harvesting and with the first end rearward for towing.
In U.S. Pat. No. 6,675,568 (Patterson) issued Jan. 13, 2004 to the present Assignees is disclosed a crop harvesting header for mounting on a propulsion vehicle such as a swather tractor or combine harvester which includes a main frame structure supporting a crop receiving table with a cutter bar across a front of the table and side drapers on the table for moving the cut crop toward a discharge location of the header. The frame is divided into a central frame portion and two separate wing frame portions each arranged for pivotal movement relative to the central portion about a pivot axis extending in a plane parallel to the forward direction and intersecting the cutter bar so that, as the wing frame portions pivot, the cutter bar flexes in the area adjacent the respective pivot axis over a small angle of the order of 4 degrees to maintain the cutter bar following the ground. The central frame portion is mounted on two spring arms for upward and twisting floating movement such that the total downward force on the ground, from that part of the weight of all of the portions of the header which is unsupported, can be varied by moving the support to change the total pressure of the header on the ground. The wing frame portions are connected to the central frame portion by interconnecting linkages which transfer weight from the wing frame portions to the springs of the central portion each including a respective balance beam arranged to balance the lifting force from the spring with the downward forces from the center portion and wing frame portion such that the downward force on a skid plate of each portion on the ground varies automatically as the total downward force is varied.
The disclosures of both of the above are incorporated herein by reference.
Many headers have integrated transportation systems including wheels which can be deployed. However these are often limited in allowable speed and in many cases the design of the header precludes the provision of an integral transport system so that a trailer is a suitable alternative.
Several companies manufacture trailers to transport windrower and combine headers.